The past fortnight has witnessed an unprecedented, open public debate in the Israeli media about whether, and when, to attack Iran's nuclear installations. While in the past six decades, Israel's wars have often been followed by debates about this or that political or military aspect, or even the justice of a given war (vide Israel's Sinai Campaign in 1956 and Israel's invasion of southern Lebanon in 1982), none have ever been preceded by major, principled, open discussion.

Nearly all Israeli Jews are agreed that a nuclear-armed Iran, with its fanatical, messianic Islamist leaders, represents a mortal threat to Israel's existence, and all—like all Western intelligence agencies—are agreed that Iran is bent on attaining nuclear weapons as quickly as possible. Some observers believe the Iranians will halt their project just short of actually producing the bombs, leaving a few screws still to be turned; I personally doubt this on the view that Iran wants a nuclear arsenal in order to project power, overawe its neighbors, deter would-be assailants and perhaps destroy Israel.

No one in Israel took seriously the American intelligence assessment of 2007 that Iran had halted its weapons production effort in 2003, and it appears that no one in Washington today adheres to that assessment. The International Atomic Energy Agency is expected this week to publish a new report putting the final nail in the coffin of that assessment. Parts of that report were leaked to the Washington Post on Monday, and they reveal that Iran has mastered the procedures needed to build a nuclear weapon in the near future. Indeed, it seems clear that the Iranians are working at breakneck speed on nuclear weaponization models, enrichment facilities and nuclear-capable delivery systems. The Russians and Chinese are understood to be trying to postpone the report's publication and/or to water down its conclusions in order to propitiate their friends in Teheran, again displaying strategic short-sightedness (not to say immorality).

The internal Israeli debate was launched in an article by Nahum Barnea, perhaps Israel's most important journalist, in the country's most popular daily, Yediot Aharonot, a fortnight ago. He briefly described the split in the Israeli hierarchy between those advocating an assault now on Iran's nuclear facilities—Prime Minister Binyamin Netanyahu and his defense minister, Ehud Barak—and those either opposed in principle to such an assault or who believe there is still time for diplomacy and sanctions to effect a halt to the Iranian program. The discord cuts across party lines and is not between traditional hawks and doves. There seems to be agreement that the Iranians are still a year and a half to two years away from the bomb, and some of Netanyahu's and Barak's opponents believe that Israel cannot, under any condition, mount an assault against the Iranian facilities without a bright green light from Washington.

But Washington has made it amply clear, most recently during Defense Secretary Leon Panetta's visit to Jerusalem last month, that it opposes unilateral Israeli military action. Commentators have said that Netanyahu and Barak declined to give Panetta an ironclad assurance that Israeli would not act alone. Barak reportedly said that when the issue is Israel's existence, Israel will do what needs to be done even if alone, whatever the views of Israel's friends abroad.

At the same time, Netanyahu and Barak continue to insist that the Iranian bomb is a global and regional threat, not merely a threat to Israel—and as such needs to be neutralized by the international community, not by Israel alone. But both men realize that the United States, after long years of relatively unsuccessful and certainly indecisive battle against Muslims in Afghanistan and Iraq (and, to a degree, Pakistan), has lost the stomach for another, possibly major, fight. President Obama may yet surprise everyone—and recent reports from London indicate that Britain may be ready to join an American-led assault on Iran, should one be launched—but no one in Israel is banking on or can bank on an American attack against the Iranian facilities. And the Iranians are daily drawing closer to the bomb.

The problems facing Netanyahu and Barak are acute. To begin with, there is strong internal opposition to an Israeli strike, and leaders of democracies are loath to go to war without a popular mandate. Leading the opposition to an attack now are reportedly the heads of the Israeli Defense Force (IDF), the General Security Service (the Shin Bet) and the Mossad, and a number of senior right-wing politicians who sit on the country's top decision-making body, the eight-man Inner Cabinet, including Moshe Yaalon, a former IDF chief of staff, and Dan Meridor, the well-respected minister in charge of the country's secret services.

Another important opponent of war now is former IDF chief of staff and defense minister Shaul Mofaz, the chairman of the Knesset's key Foreign Affairs and Defense Committee. In an interview last weekend, he told Nahum Barnes:

The danger in attacking Iran is not in the attack itself, but in what will happen in the region on the day after. A regional war is likely to break out, which from our perspective will be an existential conflict. The operation may succeed [i.e., the air force attack on the Iranian nuclear facilities]—but the patient [Israel] may die . . . Strategically speaking . . . without American leadership in the battle against the Iranian nuclear [project], without America's support and involvement, we will be taking an unreasonable risk.